1. Field of the Invention
The present invention relates to a method of forming a pattern, which method finds appropriate application in a semiconductor production process for an IC or the like, a circuit board production process for a liquid crystal, a thermal head or the like and other photofabrication lithography processes, and also relates to an actinic-ray- or radiation-sensitive resin composition, an actinic-ray- or radiation-sensitive film, a process for manufacturing an electronic device and an electronic device.
2. Description of the Related Art
Since the development of the resist for a KrF excimer laser (248 nm), in semiconductor lithography, a pattern forming method based on chemical amplification has been employed.
Shortening of the wavelength of exposure light sources and realization of high numerical apertures (high NA) for projector lenses have been advanced in order to cope with the miniaturization of semiconductor elements. To now, an exposure unit using an ArF excimer laser of 193 nm wavelength as a light source has been developed. A method (known as a liquid-immersion method) in which the space between a projector lens and a sample is filled with a liquid of high refractive index (hereinafter also referred to as an “immersion liquid”) has been proposed as a technology for enhancing the resolving power. Moreover, an EUV lithography in which the exposure is carried out using an ultraviolet of further shorter wavelength (13.5 nm) has been proposed.
In recent years, methods of forming a pattern with a developer comprising an organic solvent are being developed. For example, patent references 1 to 9 describe methods of forming a pattern, comprising the operation of developing a resist composition, in which a resin containing a repeating unit containing a group that when acted on by an acid, is decomposed to thereby produce a polar group is incorporated, with a developer comprising an organic solvent.